If you are around a person who is not exhibiting flu symptoms but comes down with the few hours after leaving exposed to flu?

If you are around a person who is not exhibiting flu symptoms but comes down with the flu a few hours after leaving, it is likely that you were not infected by that person. The flu virus typically has an incubation period of 1-4 days, which means that it takes 1-4 days for symptoms to develop after exposure to the virus. If you developed symptoms within a few hours of being exposed to someone who was not exhibiting symptoms, it is more likely that you were infected by someone else who was carrying the virus.